Chiral hypervalent iodine mediated enantioselective oxidative dearomatization of naphthols
department or school: Science, Faculty of
department or school: Chemistry, Department of
data provider: DSpace
degree campus: UBCV
creator: Jain, Nikita
issued: 2017-08-08T22:53:33Z
issued: 2017
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: This dissertation investigates and describes the hypervalent iodine mediated dearomatization of naphthols, thereby yielding diversity of spiro-heterocyclic compounds in both racemic and chiral form. The first part of this thesis discloses the synthesis of racemic spiropyrrolidines and spirolactams via oxidative amidation of corresponding naphtholic sulfonamides, employing DIB as the oxidant. Enantioselective variant of the same have been demonstrated by using in situ generated chiral hypervalent iodine to provide chiral spiropyrrolidines. A noteworthy side reaction discovered in the course of these studies is the asymmetric oxidative addition of meta-chlorobenzoic acid to the naphtholic sulfonamides. The resulting acyloxylated adducts were formed with a greater degree of asymmetric induction compared to spiropyrrolidines in the same reaction mixture. Based on the results obtained from optimization study and substrate scope, plausible mechanistic insights of both cyclization and acyloxylation reactions have been provided. The second part of this thesis unravels the spiroetherification of naphtholic alcohols, thereby yielding spiroethers both in racemic and chiral form. Chiral hypervalent iodine reagents generated in situ provided a range of spiroethers with excellent ee’s and high yields. These chiral oxidants have been evaluated for kinetic resolution of naphtholic primary alcohols bearing stereogenic center at β-position in the side chain.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/62521
note: Chiral Hypervalent Iodine Mediated Enantioselective Oxidative Dearomatization of Naphthols by Nikita Jain A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in The Faculty of Graduate and Postdoctoral studies (Chemistry) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) August 2017 © Nikita Jain, 2017 ii Abstract This dissertation investigates and describes the hypervalent iodine mediated dearomatization of naphthols, thereby yielding diversity of spiro-heterocyclic compounds in both racemic and chiral form. The first part of this thesis discloses the synthesis of racemic spiropyrrolidines and spirolactams via oxidative amidation of corresponding naphtholic sulfonamides, employing DIB as the oxidant. Enantioselective variant of the same have been demonstrated by using in situ generated chiral hypervalent iodine to provide chiral spiropyrrolidines. A noteworthy side reaction discovered in the course of these studies is the asymmetric oxidative addition of meta-chlorobenzoic acid to the naphtholic sulfonamides. The resulting acyloxylated adducts were formed with a greater degree of asymmetric induction compared to spiropyrrolidines in the same reaction mixture. Based on the results obtained from optimization study and substrate scope, plausible mechanistic insights of both cyclization and acyloxylation reactions have been provided. The second part of this thesis unravels the spiroetherification of naphtholic alcohols, thereby yielding spiroethers both in racemic and chiral form. Chiral hypervalent iodine reagents generated in situ provided a range of spiroethers with excellent ee’s and high yields. These chiral oxidants have been evaluated for kinetic resolution of naphtholic primary alcohols bearing stereogenic center at β-position in the side chain. iii Lay summary Hypervalent iodine reagents are used as environmentally friendly, mild and selective oxidants for various synthetic conversions. This thesis describes their …
has type: Thesis/Dissertation
date issued: 2017-09
is shown at: 10.14288/1.0351990
language: eng
degree discipline: Chemistry
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/62521